Lecithin may become contaminated with e.g. poly-aromatic hydrocarbons (PAH's), pesticides and other contaminants during its extraction process from oil seeds. Some of these contaminants, and especially PAH's, can be carcinogenic and pose a problem when the lecithin is to be used in food and animal feed, and especially in infant food products.
Methods for removing PAHs from liquids have been described in the art. For example, U.S. Pat. No. 6,270,676 describes a process for removing ethers and/or polycyclic aromatic hydrocarbons from water. The process requires adsorbing the contaminants on an adsorber resin of divinyl benzene/styrene copolymer, then desorbing the adsorbed contaminants with steam and finally regenerating the adsorber resin. The methods of the prior art are however not directly applicable to lecithin. This is because lecithin is too viscous. As such, putting the lecithin through a packed column or a filter is very difficult.
It is thus an object of the present invention to provide a method for the purification of lecithin that is capable of effectively and economically removing contaminants such as PAH's.